JPH01163756A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain picture images contg. no fog nor brush mark stably for over multiple numbers of image forming process, permitting thereby heat fixing at lower temp. by using a toner contg. a specified block copolymer or a graft copolymer. CONSTITUTION:A visible picture image is formed by the development of an electrostatic latent image on a carrier of the latent image by using a toner contg. a block or graft copolymer consisting of a crystalline polyester and an ionically crosslinked amorphous vinyl polymer (A). (Co)polymers contg. a styrenic or (meth)acrylic monomer may be used for the polymer (A). The value of [weight average mol.wt. (Mw)]/[number average mol.wt. (Mn)] of the polymer A is pref. >=3.5, and a polymer having at least two max. values in the mol.wt. distribution is also desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an image forming method applied to, for example, electrophotography, electrostatic printing, electrostatic recording, and the like.

[Technology background]

For example, in electrophotography, an electrostatic latent image is usually formed on an electrostatic latent image carrier made of a photoconductive photoreceptor by charging and exposure, and then this electrostatic latent image is transferred using toner, which is a colored particle. After development, the resulting toner image is usually transferred to a recording material such as paper and then fixed to form a visible image.

Conventional methods for fixing toner images include a method in which the toner is heated and melted in a non-contact state using a heater;
Methods of fixing the toner by dissolving the toner with an organic solvent, methods of fixing the toner by pressurizing the toner, and so-called heated roller fixing methods of directly contacting the toner with a heating roller and melting and pressing the toner to fix it are known. A heated roller fixing method is preferred from the viewpoint of high thermal efficiency and high-speed fixing.

However, in recent years, efforts have been made to (a) suppress deterioration of copying machines due to overheating, and (b) shorten the warm-up time required for the heating roller to rise to a temperature capable of fixing after the heating roller fixing device is activated. (c) To reduce the temperature drop of the heating roller due to heat absorption by recording materials such as paper, making it possible to form stable images many times in a row; and (d) to improve copying machine performance. From the viewpoint of downsizing and improving safety, there is a strong demand for reducing power consumption of a heater incorporated in a fixing device to enable fixing processing at a lower temperature of a heating roller.

Therefore, toners are required to (1) be capable of achieving good fixing at lower temperatures, that is, have excellent low-temperature fixing properties, and basically meet the following conditions: is necessary.

(2) In the heating roller fixing method, which is preferable as a fixing method, there is an offset phenomenon, that is, a part of the toner forming the image is transferred to the surface of the heating roller during fixing, and this is transferred again to the recording material that is sent next. Since the phenomenon of smearing the image (under-offset, which occurs when heating is insufficient, and hot offset, which occurs when heating is excessive), is likely to occur, it is necessary to improve the toner's ability to prevent transfer to the heating roller, that is, offset resistance. To cause it to be granted.

(3) It should be able to exist stably as a powder without agglomerating under the environmental conditions of use or storage, that is, it should have excellent storage stability.

(4) Good triboelectric charging stability and excellent developability.

[Conventional technology]

Conventionally, however, the following techniques have been proposed.

■Technology to use a resin made by chemically bonding a crystalline part with a melting point Tm of 45 to 150°C and a non-quality part with a glass transition point Tg of 0°C or less as a resin for toner (Japanese Patent Laid-Open No.
(Refer to Publication No.-87032).

■As a resin for toner, a crystalline portion with a melting point T1Tl of 45 to 90°C is chemically combined with a non-quality portion having a glass transition point Tg which is 10°C higher than the melting point Tm of the crystalline portion. Technology using resin (Japanese Unexamined Patent Publication No. 1987-
(See Publication No. 3446).

■Technology using a graft polymer of a crystalline polymer obtained from ethylene, propylene, and vinyl acetate and a vinyl polymer as a resin for toner (Japanese Patent Laid-Open No. 56-154740)
(see publication).

(2) A technique using a graft polymer of a crystalline polymer obtained from ethylene, propylene, and vinyl acetate, an unsaturated polyester, and a vinyl polymer as a toner resin (see Japanese Patent Laid-Open No. 8549/1983).

■ As a toner resin, a block copolymer or graft copolymer of a hard component and a soft component, a non-grade resin with a glass transition point Tg of 50°C or higher and compatible with the hard component, and a melting point Tm Technology using a mixture of the hard component and an incompatible crystalline resin at 60°C or higher
(See Publication No. 32447).

■As a toner resin, a graft copolymer obtained by graft polymerizing a vinyl polymer to a crystalline polymer obtained from ethylene, propylene, and vinyl acetate, and a monomer common to the monomer of the graft copolymer are used. A technique using a mixture of a crosslinked polymer obtained by copolymerizing a vinyl monomer containing a majority of divinyl monomers and a divinyl monomer (JP-A-60-2
(See Publication No. 63953).

■As a toner resin, the surface tension γ of one of the polymers constituting the main chain and the polymer constituting the side chains is 3.
4 or more and the surface tension Ts of the other polymer is less than 34 (Japanese Unexamined Patent Publication No. 59-135
(See Publication No. 478).

(*Comment: JP-A-50-92139 is a liquid developer and cannot be directly compared as a prior art, so I don't think it is necessary to mention it.) [Problems to be solved by the invention] However, the above For technologies ① to ②, [1] low temperature fixing properties, (2) offset resistance, (3) storage stability, and (4)
) It is still difficult to obtain toners that are fully satisfactory in all respects of developability.

In other words, in the above technology (2), the toner resin has high tackiness, so it has poor storage stability even when wiped at room temperature, and offset phenomenon tends to occur during fixing.Also, the stability of triboelectric charging is poor, making it difficult to develop. As a result, the resulting image becomes blurred with a lot of fog.

With the above technology (■), the toner resin is soft, resulting in poor triboelectric charging stability and poor developability.In addition, an offset phenomenon is likely to occur during fixing, and the resulting image has a lot of fog. It becomes unclear.

In the above-mentioned techniques (1), (2) and (2), developability is poor due to poor triboelectric charging properties, and as a result, the resulting images are unclear with image gaps and the like.

In the above technique (2), since the toner is used for pressure fixing, there is a problem in that the offset phenomenon occurs significantly in the heat roller fixing method.

In the above technique (2), the mold releasability at low temperatures is poor, so-called under-offset resistance is poor, and it is difficult to obtain a stable image over a long period of time.

On the other hand, in order to improve low-temperature fixing properties, anti-offset properties, and storage stability, there is a technology to use a resin obtained by reacting a polymer having a carboxyl group with a metal compound as a resin for toner (Japanese Patent Laid-Open No. Publication No. 57-178250, JP-A-61-1
10155, Japanese Patent Application Laid-Open No. 110156/1983) was proposed. .

However, with this technique (2), although the hot offset resistance and storage stability are good, the under-offset resistance is poor because the mold releasability and fixing properties at low temperatures are poor.

In contrast, the present inventor has developed a toner resin by using a block copolymer or a graft copolymer formed by chemically bonding a crystalline polyester and an ionically bonded amorphous vinyl polymer as a toner resin. We have developed a technology that improves the low-temperature fixing properties, offset resistance, and blocking resistance of .

However, new problems have been discovered with such toners. In other words, since the above-mentioned toner contains crystalline polyester, it is difficult to negatively charge the toner with an appropriate amount of charge under high temperature and high humidity. When an image is formed using a selenium photoreceptor, there is a problem in that streaks (broom marks) appear on the image as if they were swept with a broom, resulting in poor image quality.

The present invention was made based on the above-mentioned circumstances, and provides (1) low temperature fixing properties, (2) anti-offset properties, (3)
The present invention provides an image forming method that is fully satisfactory in all aspects of (4) preservability and (4) developability.

[Means for solving problems]

The image forming method of the present invention uses a toner containing a block copolymer or a graft copolymer formed by chemically bonding a crystalline polyester and an ionically crosslinked amorphous vinyl polymer. It is characterized by developing an electrostatic latent image formed on a latent image carrier made of a conductive semiconductor.

[Function and effect of the invention]

According to the image forming method of the present invention, since an electrostatic latent image formed on a latent image carrier made of an organic photoconductive semiconductor is developed using a specific toner, (1) low temperature fixability, ( 2)
Excellent effects are exhibited in all aspects of offset resistance, (3) storage stability, and (4) developability.

Therefore, good heat fixing is possible at a lower temperature, and good images without fog or blemish marks can be stably formed many times.

In other words, the ionically crosslinked amorphous vinyl polymer has strong crosslinks and strong properties when not heated, and therefore suppresses the tackiness that crystalline polyester has. The effect is extremely large, resulting in improvements in storage stability and triboelectric charging stability.
When it is heated by heat fixing, the moderate viscoelasticity of the ionically crosslinked amorphous vinyl polymer improves offset resistance, and the ionic crosslinks of the amorphous vinyl polymer are shared. It has a bonding force smaller than that of a bond and is easily broken by heating, and also exhibits excellent low-temperature fixing properties due to the synergistic effect of crystalline polyester's good low-temperature melting properties and good permeability to recording materials such as paper.

Because the toner exhibits excellent low-temperature fixing properties,
When applying the heat roller fixing method, the set temperature of the heat roller can be lowered than before, which not only improves the durability of the heat roller, but also speeds up image formation by shortening warm-up time. It becomes possible.

Furthermore, even when images are formed on both sides of a recording material, the images can be stably formed without causing curls, wrinkles, or the like.

Since the block copolymer or graft copolymer contained in the toner has crystalline polyester as its constituent component, the triboelectric charging properties of the toner and the charging properties of the latent image carrier made of an organic photoconductive semiconductor As a result, excellent developability is exhibited and the occurrence of blemishes is prevented.

[Specific structure of the invention]

The toner used in the present invention is a block copolymer or graft copolymer formed by chemically bonding a crystalline polyester and an ionically crosslinked amorphous vinyl polymer (hereinafter also referred to as "ionically crosslinked amorphous vinyl polymer"). It contains a copolymer as an essential component.

In the present invention, a one-component developer consisting only of toner,
Alternatively, any two-component developer consisting of toner and carrier can be used.

The ionically crosslinked amorphous vinyl polymer needs to have a functional group to form a block copolymer or graft copolymer with the crystalline polyester. Such functional groups include, for example, carboxyl group, hydroxyl group, amino group,
Preferred examples include epoxy groups.

Examples of monomers having such functional groups include acrylic acid, β, β-dimethylacrylic acid, α-ethyl acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, crotonic acid, hydroxyethyl methacrylate, and amber. Examples include acid monoacryloyloxyethyl ester, N-hydroxyethylacrylamide, N-methylolacrylamide, p-aminostyrene, glycidyl methacrylate, and the like. A monomer having such a functional group is contained in a monomer composition for obtaining an ionically crosslinked amorphous vinyl polymer in an amount of 0.1 to 20 mol%, preferably 0.
．． It is preferably used in a proportion of 5 to 10 mol%.

Further, the ionically crosslinked amorphous vinyl polymer needs to be an amorphous vinyl polymer having a structure crosslinked by ionic bonds. Examples of the vinyl polymer as a backbone for forming an ionic crosslinked structure include polystyrene, polymethyl methacrylate, polymethyl acrylate, polyvinyl chloride,
Examples include polyvinyl acetate, polyacrylonitrile, and others. Among these, a vinyl polymer obtained using at least one selected from styrene monomers, acrylic acid monomers, and methacrylic acid monomers as an essential component is preferred. In particular, it is preferable that a polyvalent metal compound reacts with the carboxyl group of the vinyl polymer having a carboxyl group to form an ionic crosslink.

In order to obtain such a vinyl polymer having a carboxyl group, polymerization may be carried out using, in addition to the above-mentioned monomers, a monomer selected from acrylic acid or methacrylic acid and derivatives thereof as an essential component.

For example, a half-ester compound having a structure obtained by an esterification reaction between an acrylic ester or methacrylic ester having a hydroxyl group, or a derivative thereof, and a dicarboxylic acid compound can be mentioned as a preferable compound. According to such a half-ester compound, a carboxyl group is introduced at a position that has little effect on the main chain structure, so
The steric hindrance of the chemical structure is reduced, and as a result, the reaction between the carboxyl group and the polyvalent metal compound proceeds efficiently to form ionic crosslinks, making it possible to obtain an ionic crosslinked amorphous vinyl polymer with a good crosslinked structure. can.

Examples of the styrenic monomer for obtaining the vinyl polymer include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene,
p-ethylstyrene, 2゜3-dimethylstyrene, 2.
4-dimethylstyrene, p-n-butylstyrene, p-
tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene ,p-
Examples include chlorstyrene and 3,4-dichlorostyrene. These monomers may be used alone or in combination.

Examples of acrylic esters or methacrylic esters for obtaining the above vinyl polymer include metinope acrylate, ethyl acrylate, ptynope acrylate, inbutynope acrylate, propyl acrylate, octyl acrylate, dodecyl acrylate, and acrylic acid. lauryl, 2-ethylhexyl acrylate, stearyl acrylate,
Acrylic acid esters such as acrylic 112-2-chloroethyl, phenyl acrylate, and methyl α-chloroacrylate; for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutinope methacrylate, and octyl methacrylate. , dodecyl methacrylate, lauryl methacrylate, methacrylic acid-2
- Ethylhexynope methacrylic acid esters such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; and the like.

Examples of the compound having a carboxyl group forming the half-ester compound include aliphatic dicarboxylic acid compounds such as malonic acid, succinic acid, and glutaric acid, and aromatic dicarboxylic acid compounds such as phthalic acid.

A half-ester compound can be obtained by subjecting these compounds to an esterification reaction with an acrylic ester or methacrylic ester having a hydroxyl group, or a derivative thereof. The dicarboxylic acid compound may have a hydrogen atom substituted with a halogen group element, a lower alkyl group, an alkoxy group, or the like, or may be an acid anhydride. The derivative of acrylic acid or methacrylic acid having a hydroxyl group may be one in which 1 or 2 moles or more of alkylene oxide such as ethylene oxide or propylene oxide is added to acrylic acid or methacrylic acid, or acrylic acid or methacrylic acid. It may also be a hydroxyalkyl ester obtained by subjecting a dihydric alcohol such as propylene glycol to an esterification reaction.

Preferred half-ester compounds include, for example, succinic acid monoacryloyloxyethyl ester, succinic acid monoacryloyloxypropyl ester, glutaric acid monoacryloyloxyethyl ester, phthalic acid monoacryloyloxyethyl ester, phthalic acid monoacryloyloxypropyl ester, and succinic acid. Examples include monomethacryloyloxyethyl ester, succinic acid monomethacryloyloxypropyl ester, glutaric acid monomethacryloyloxyethyl ester, phthalic acid monomethacryloyloxyethyl ester, and phthalic acid monomethacryloyloxypropyl ester.

The metal element of the polyvalent metal compound to be reacted with the carboxyl group of the vinyl polymer having a carboxyl group is as follows:
For example, Cu, Ag, Be, Mg, Ca, Sr
.

Ba, Zn, Cd, AI, Ti, Ge, S
n, V, Cr, Mo, Mn, Fe, Ni,
Co, Zr, Se, etc. can be mentioned.

Among these, alkaline earth metals (Be, Mg,
Ca.

Sr, Ba) and zinc group elements (Zn, Cd) are preferred, with Mg and Zn being particularly preferred.

Examples of polyvalent metal compounds containing these metals include:
Fluorides, chlorides, chlorates, bromides, iodides, oxides, hydroxides, sulfides, sulfites, sulfates, selenides, tellurides, nitrides, nitrates, phosphides of the above metal elements, Examples include phosphinates, phosphates, carbonates, orthosilicates, acetates, oxalates, and lower alkyl metal compounds such as methyl compounds or ethyl compounds. Among these, acetates of the above metal elements and oxides of the above metal elements are particularly preferred.

The amount of the polyvalent metal compound added varies depending on the type and amount of monomers constituting the vinyl polymer having a carboxyl group, so it cannot be specified as one type, but for example, it is It is about 0.1 to 1 mole.

In order to react a polyvalent metal compound with the carboxyl group of a vinyl polymer having a carboxyl group, for example, the polyvalent metal compound is added to a solution containing a vinyl polymer having a carboxyl group obtained by polymerization by a solution polymerization method. A dispersion solution of the metal compound or the polyvalent metal compound is mixed, the temperature is raised, and the solvent is removed for about 1 to 3 hours, and the temperature in the reaction system reaches about 150 to 180°C for more than 1 hour. It is best to maintain this temperature to complete the reaction. In some cases, a polyvalent metal compound may be present in the reaction system together with a solvent before starting the polymerization of the vinyl polymer having carboxyl groups, or the carboxyl groups obtained by the above-mentioned solvent removal treatment may be The vinyl polymer and the polyvalent metal compound may be melt-kneaded using a roll mill, kneader, extruder, etc. to react with each other.

In this way, the ionically crosslinked amorphous vinyl polymer obtained by the reaction of the vinyl polymer having carboxyl groups and the polyvalent metal compound is produced by the reaction between the carboxyl groups and polyvalent metal atoms of the vinyl polymer having carboxyl groups. are combined by ionic bonds, and a kind of crosslinked structure is formed by these ionic bonds. This ionic bond is a much looser bond than a covalent bond.

Further, from the viewpoint of further improving low-temperature fixing properties and anti-offset properties, it is preferable that the ionically crosslinked amorphous vinyl polymer has at least two maximum values in its molecular weight distribution. Specifically, it has a molecular weight distribution that can be divided into at least two groups: a low molecular weight component with a small maximum molecular weight value and a high molecular weight component with a large molecular weight maximum value, and has a molecular weight distribution that is measured by gel verminylation chromatography (GPC). In the molecular weight distribution curve, at least one maximum value is within a range of approximately 2.000 to 20.000, and at least one maximum value is within a range of approximately 100.000 to 1.000.
It is preferable to have at least two maximum values, such as within a range of about 000. In addition, since the ionically crosslinked amorphous vinyl polymer can be made even stronger by the above-mentioned high molecular weight component, it has a great effect of suppressing toner particle destruction due to friction with the carrier or collision with the latent image carrier. As a result, generation of fine powder that causes the filming phenomenon is suppressed. The proportion of the high molecular weight component is preferably 15% by weight or more, particularly preferably 15 to 50% by weight of the ionically crosslinked amorphous vinyl polymer.

When the ionically crosslinked amorphous vinyl polymer is composed of a high molecular weight component and a low molecular weight component as described above, it is preferable that a carboxyl group that reacts with a polyvalent metal compound is introduced into at least the low molecular weight component. . That is,
The destruction of toner particles caused by friction with the carrier or collision with the surface of the latent image carrier is mainly caused by relatively brittle components of low molecular weight in the toner particles, and the details of such low molecular weight components will be described later. By crosslinking the toner with a polyvalent metal compound through so-called ionic bonds to make it tough, it is possible to effectively prevent the generation of fine powder that causes the filming phenomenon caused by the destruction of toner particles.

Further, in the ionically crosslinked amorphous vinyl polymer, the ratio Mw/Mn between the weight average molecular weight Mw and the number average molecular weight Mn is preferably 3.5 or more, particularly preferably 4 to 40. When the ratio Mw/Mn is too small, sufficient offset resistance and durability cannot be obtained. Here, the values of the weight average molecular weight IMw and the number average molecular weight Mn can be determined by various methods, and there are slight differences depending on the measurement method, but in the present invention, the values determined by the following measurement method are used. It is.

The weight average molecular weight Mw, number average molecular weight Mn, and peak molecular weight are measured by Sunawachi Kerr Permuen Yong Chromatography (GPC) under the conditions described below. At a temperature of 40°C, the solvent (tetrahydrofuran) is added every minute. Flowed at a flow rate of 1.2-, concentration 0.2 g
3 mg of a /20- tetrahydrofuran sample solution is injected and measured. When measuring the molecular weight of a sample, select measurement conditions in which the molecular weight of the sample falls within a range where the logarithm of the molecular weight and the count number of the calibration curve prepared using several types of monodispersed polystyrene standard samples are linear. . The reliability of the measurement results was determined using the NB5706 polystyrene standard sample (weight average molecular weight Mw = 28.8X10', number average molecular weight Mn = 13.7 xio', Mw /Mn = 2.1) measured under the above measurement conditions.
This is confirmed by checking that the value of the ratio MIII/Mn in 1) is 2.11±0.10.

Moreover, any column may be used as the GPCO column as long as it satisfies the above conditions. Specifically, for example, TSK-GEL, GMH (manufactured by Toyo Soda Co., Ltd.), etc. can be used. Note that the solvent and measurement temperature are not limited to the above conditions, and may be changed to appropriate conditions.

As the ionically crosslinked amorphous vinyl polymer, one having at least two maximum values in the molecular weight distribution curve can be preferably used as described above, but as a method for obtaining such an ionically crosslinked amorphous vinyl polymer, in particular Not limited. For example, a first stage polymerization is performed to obtain either a high molecular weight component with a large maximum molecular weight value or a low molecular weight component with a small maximum molecular weight value, and one component obtained thereby is used to obtain the other component. by dissolving it in a monomer composition for a second stage of polymerization and thereby producing the other component, resulting in a polymer having at least two maximum values in the molecular weight distribution curve. Can be done.

It is presumed that the polymer obtained by the two-stage polymerization is a mixture of a low molecular weight component and a high molecular weight component uniformly at the molecular level. This two-stage polymerization can be carried out by, for example, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, etc., and a solution polymerization method is particularly preferred.

Furthermore, a polymer having at least two maximum values in the molecular weight distribution curve can also be obtained by mixing a low molecular weight polymer component with a small maximum molecular weight value and a high molecular weight polymer component with a large maximum molecular weight value. However, since the polymer obtained by mixing may not be uniformly mixed at the molecular level, it is preferable to use the two-stage polymerization described above.

Further, from the viewpoint of further improving low-temperature fixability, offset resistance, and durability, the glass transition point Tg of the ionically crosslinked amorphous vinyl polymer is preferably 50 to 100°C, particularly preferably 50 to 85°C. Here, the glass transition point Tg is a value measured based on differential scanning calorimetry (DSC), and specifically, for example, rDSC-20J (
(manufactured by Seiko Electronics Co., Ltd.) at a heating rate of 10°C/m.
It refers to the temperature at the intersection of the extension line of the baseline below the glass transition point and the tangent line showing the maximum slope from the rising part of the peak to the apex of the peak when measured at in.

The crystalline polyester that forms a block copolymer or graft copolymer with the above-mentioned ionically crosslinked amorphous vinyl polymer has a crystal structure in at least a part of the polyester, and is a homopolymer or copolymer. At least the l component is crystalline, that is, it includes partially crystallized components, and exhibits a sharp and clear melting point, and in the solid state at a temperature below the melting point, it exhibits clouding due to the crystallized portion.

As such crystalline polyester, polyalkylene polyester is particularly preferred from the viewpoint of low-temperature fixability and fluidity. Specifically, for example, polyethylene sebacate, polyethylene adipate, polyethylene adipate, polyethylene succinate, polyethylene p-(carbophenoxy) undecaate, polyhexamethylene sebacate.
Polyhexamethylene sebacate, polyhexamethylene decanedioate, polyoctamethylene dodecanedioate, polynonamethylene azelate, polydecamethylene adipate, polydecamethylene azelate, polydecamethylene succinate, polydecamethylene Sebacate,
Polydecamethylene succinate, polydecamethylene dodecanedioate, polydecamethylene octadecanedioate, polytetramethylene sebacate, polytrimethylene dodecanedioate, polytrimethylene octadecanedioate, polytrimethylene ocdylate, polyhexamethylene -decamethylene sebacate, polyol sidedecamethylene-2-methyl-1,3-propane-dodecanedioate, and the like.

The melting point Tm of the crystalline polyester is preferably 50 to 120°C, particularly 50 to 100°C. When the melting point Tm is too small, the blocking resistance tends to deteriorate, and when the melting point Tm is too large, the low-temperature fixability tends to deteriorate. Note that the melting point Tm of this crystalline polyester was measured in a state where it was not bonded to an ionically crosslinked amorphous vinyl polymer. Note that melting point Tm refers to differential scanning calorimetry (DSC).
), 10 mg of sample was heated at a constant heating rate (10°C/m
It refers to the melting peak value when heated at 1n).

In addition, the crystalline polyester has a weight average molecular weight Mw of 5.000 to 50.000, a number average molecular weight Mn
is preferably 2.000 to 20.000.

The proportion of crystalline polyester in the block copolymer or graft copolymer is 3 to 50% by weight, especially 5% by weight.
~40% by weight is preferred. When the proportion of crystalline polyester is too small, low-temperature fixing properties tend to deteriorate, while when it is too large, anti-offset properties tend to deteriorate.

It is preferable that the crystalline polyester and the ionically crosslinked amorphous vinyl polymer are substantially incompatible.

Note that "substantially incompatible" means that the crystalline polyester and the ionically crosslinked amorphous vinyl polymer are not sufficiently dispersed, and specifically, for example, S,
P, value (R, F, Fedors, Polym.

Eng, Sci, 14. (2) 147 (
1974)] is greater than 0.5.

In order to obtain a block copolymer or a graft copolymer formed by chemically bonding a crystalline polyester and an ionically crosslinked amorphous vinyl polymer, for example, a coupling reaction between terminal functional groups may be performed in a head-to-tail manner. They can be bonded directly to each other or via a terminal functional group and a bifunctional coupling agent. For example, a urethane bond formed by a reaction between a polymer whose terminal group is a hydroxyl group and a diisocyanate, a reaction between a polymer whose terminal group is a hydroxyl group and a dicarboxylic acid, or a reaction between a polymer whose terminal group is a carboxyl group and a glycol. The bond can be formed by an ester bond formed by ester bond, or another bond formed by reaction of a polymer whose terminal group is a hydroxyl group with phosgene or dichlorodimethylsilane.

Such coupling agents include, for example, difunctional incyanates such as hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, toridine diisocyanate, naphthylene diisocyanate, inphorone diisocyanate, xylylene diisocyanate; for example, ethylene diamino, hexamethylene diisocyanate, Difunctional aminos such as phenylene diamino;
For example, oxalic acid, succinic acid, adipic acid, sebacic acid,
Difunctional carboxylic acids such as terephthalic acid and isophthalic acid;
For example, ethylene glycone propylene glycol, butanediol, bentanediol, hexanediol,
Difunctional alcohols such as cyclohexane dimetatool, p-xylylene glycol; Difunctional acid chlorides such as terephthalic chloride, isophthalic chloride, adipic chloride, sebacic chloride; such as diisothiocyanate, bisketene, Other bifunctional coupling agents such as biscarbodiimide can be mentioned.

The coupling agent is preferably used in an amount of 1 to 10% by weight, particularly 2 to 7% by weight, based on the total amount of the crystalline polyester and the ionically crosslinked amorphous vinyl polymer. When the proportion of the coupling agent is too large, the softening point of the obtained block copolymer or graft copolymer becomes too high, which tends to deteriorate low-temperature fixing properties, and on the other hand, when the proportion of the coupling agent is too small, the anti-offset properties tend to deteriorate.

In the present invention, the above-mentioned specific block copolymers or graft copolymers are used as toner resins, but other resins may be used in combination as necessary. However, it is preferable that the proportion of the block copolymer or graft copolymer in the toner is 30% by weight or more.

The toner may contain various additives as necessary. Examples of such additives include colorants, charge control agents, and fixability improving agents.

Examples of colorants include carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green offsalate,
Mention may be made of lamp black, rose bengal, mixtures thereof, and others.

Examples of the charge control agent include metal complex dyes, nigrosine dyes, and ammonium compounds.

Fixability improvers include polyolefins, fatty acid metal salts, fatty acid ester rings and fatty acid ester waxes, partially saponified fatty acid esters, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, polyamide waxes, and polyhydric alcohol esters. Examples include nope silicone fess, aliphatic fluorocarbon, and the like. Particularly preferred is a wax having a softening point of 60 to 150°C according to the ring and ball method (JIS K 2531).

Furthermore, inorganic fine particles may be added to the toner as a fluidity improver or an abrasive. The average diameter of the primary particles (particles separated into individual unit particles) of such inorganic fine particles is preferably 5 μm to 2 μm, particularly 5 μm.
It is preferable that the amount of waste is U to 500 μ.

In addition, the specific surface area according to the BET method is 20 to 500 m2/
g is preferred. The proportion of inorganic fine particles added to the toner is preferably 0.01 to 5% by weight, particularly 0.01 to 2.0% by weight.
0% by weight is preferred.

Specific examples of inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, and oxide. Examples include chromium, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Particularly preferred is silica fine powder.

This fine silica powder is a fine powder having a 5i-0-3i bond, and includes those produced by a dry method or a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, etc. may be used, but those containing 5uch at 85% by weight or more are preferable. As specific examples of fine silica powder, those having a hydrophobic group on the surface are preferable, such as Eva "Aerosil R-9724, 'Aerobl R
Commercial products such as "-974", "Aerosil R-805J", "Aerosil R-812J (manufactured by Nippon Aerosil Co., Ltd.), and "Talanox 500J (manufactured by Talco Co., Ltd.) can be preferably used.In addition to these, silane It is also possible to use fine silica powder whose surface has been treated with a titanium-based coupling agent, a silicone oil having an amino group in its side chain, or the like.

Further, a cleaning property improving agent may be further added and mixed in the toner. Examples of such cleaning property improvers include zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, and polymer particles such as methyl methacrylate particles and styrene particles.

Further, when obtaining a magnetic toner, fine particles of a magnetic substance are contained in the toner particles. Examples of magnetic materials include iron, ferrite, magnetite, and other ferromagnetic metals or alloys such as ferromagnetism, or compounds containing these elements. Alloys that exhibit ferromagnetic properties when applied, such as evamanganese-copper-aluminum, manganese-
Mention may be made of a type of alloy called Heusler alloy containing manganese and copper such as copper-tin, chromium dioxide, and others. The magnetic material is preferably contained in a uniformly dispersed form of fine powder having an average particle size of 0.1 to 1 μm.

The content of the magnetic material is 10 to 70% by weight of the toner.
is preferable, particularly preferably 20 to 50% by weight.

The above toner can be manufactured, for example, as follows. That is, a toner resin or a resin to which additives are added as necessary is melt-kneaded using an extruder, cooled, and then finely pulverized using a jet mill, etc., and then classified to produce toner of a predetermined particle size. can be manufactured.

Alternatively, a toner having a predetermined particle size can be produced by melt-kneading the toner using an extruder and then spraying it in a molten state using a spray dryer or dispersing it in a liquid.

In the case of a two-component developer, the toner and carrier are mixed to form the developer. Such a carrier is not particularly specified, and conventionally known carriers can be used. Specifically, there are uncoated carriers made of only magnetic particles, resin-coated carriers in which the surfaces of magnetic particles are coated with resin, and magnetic material-dispersed carriers in which magnetic particles are dispersed in resin particles. A carrier etc. can be used. The average particle size of the carrier is 20 to 200
The average particle size (weight) of the carrier is preferably a value measured using "Microtrac" (manufactured by Nikkiso Co., Ltd.).

Magnetic particles used in the carrier include, for example, ferromagnetic metals such as iron, nickel, and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, and materials that do not contain ferromagnetic elements but are properly heat-treated. Examples of such alloys include alloys that exhibit ferromagnetism due to this, such as alloys called Heusler alloys such as manganese-copper-aluminum and manganese-copper-tin, and fine particles such as chromium dioxide.

Examples of the resin used for the resin-coated carrier include vinylidene fluoride-tetrafluoroethylene copolymer, tetrafluoroethylene, and methyl methacrylate-methacrylate.
Fluorine resins such as 112-1,1-dihydroxyperfluoroethyl copolymer, styrene-methacrylic acid-1,1,3-)dihydroxyberfluoro-n-propyl copolymer; for example, polystyrene, styrene-methyl methacrylate, etc. Polymers, vinyl resins such as styrene-n-butyl acrylate copolymer, styrene-2-ethylhexyl copolymer, polymethyl methacrylate, styrene-bucdiene copolymer; for example, silane coupling agent, silicone oil, silicone oil ,silicone rubber,
Silicone compounds such as silicone resins or cured products thereof; and the like can be mentioned. The above-mentioned substances may be used alone or in an appropriate combination of multiple types.

In the present invention, an image is formed by developing a negative electrostatic latent image formed on the surface of an organic latent image carrier using the above toner.

An organic latent image carrier is usually constructed by laminating a photosensitive layer containing a photoconductive semiconductor made of an organic compound on a conductive support. The photosensitive layer is preferably constructed by dispersing and containing a photoconductive semiconductor made of an organic compound in a binder made of resin.

The photosensitive layer includes a carrier generation layer containing a carrier generation substance that absorbs visible light and generates charged carriers, and a carrier generation layer that transports either or both of positive and negative carriers generated in this carrier generation layer. It is preferable to use a so-called functionally separated type photosensitive layer configured by combining a carrier transport layer containing a carrier transport substance. In this way, by assigning the two basic functions necessary for the photosensitive layer, namely carrier generation and carrier transport, to separate layers, the range of materials that can be used in the composition of the photosensitive layer is widened, and each It becomes possible to independently select the substance or material system that optimally performs the function.
In addition, by doing so, various characteristics required in the image forming process, such as high surface potential when charged, high charge retention ability, high photosensitivity, and high stability during repeated use, etc. It becomes possible to construct an organic latent image carrier having excellent properties.

As carrier-generating substances in the photosensitive layer, for example, anthanthrone pigments, perylene derivatives, phthalocyanine pigments, bisazo pigments, indigoid dyes, etc. can be used. Examples of carrier transport substances include carbazole derivatives, oxadiazole derivatives, triarylamino derivatives, polyarylalkane derivatives,
Hydrazone derivatives, pyrazoline derivatives, stilbene derivatives, styryl triarylamino derivatives, etc. can be used. The thickness of the carrier generation layer is usually 0 to 2J.
The carrier transport layer preferably has a thickness of 1 to 30 μm.

When forming a photosensitive layer by dispersing a photoconductive semiconductor made of an organic compound in a binder made of a resin, examples of the resin that can be used as the binder include polyethylene, polypropylene, acrylic resin, methacrylic resin, chloride resin, etc. Addition polymer resins, polyaddition resins, polycondensation resins such as vinyl resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, and these Copolymer resins containing two or more of the repeating units of the resin, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, styrene-acrylic copolymer resins, etc. Examples include insulating resins such as , or polymeric organic semiconductors such as polyamide (N-vinylcarbazole).

In the organic latent image carrier, for example, a metal sheet made of aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, steel, brass, etc. can be used as the conductive support. can.

The specific structure of the organic latent image carrier is not particularly limited, and various structures can be adopted.

Also, the surface potential when charged is, for example, -400 to -
An organic latent image carrier having a voltage of 1000V can be particularly preferably used.

In the fixing step, a heated roller fixing method can be preferably employed. A heating roller fixing device used in the heating roller fixing method is usually composed of a heating roller, a pressure roller disposed in opposition to the heating roller, and a heat source. Further, a cleaning roller is arranged opposite to the heating roller as necessary. While maintaining the temperature of the heating roller within a certain range using a heating source, the recording material on which the toner has been transferred is passed between the heating roller and the pressure roller, so that the toner is brought into direct contact with the heating roller and the toner is removed. is heat-fixed onto the recording material. The surface material of the heating roller is preferably a fluorine-based material or a silicone-based material, and the synergistic effect with the above-mentioned specific toner can significantly improve the durability of the heating roller fixing device.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited to these Examples.

Production of crystalline polyester> (1) Crystalline polyester 1 1500 g of sebacic acid and 964 g of hexamethylene glycol were mixed in a 5β capacity vessel equipped with a thermometer, a stainless steel stirrer, a glass nitrogen inlet tube, and a down-flow condenser. This flask was placed in a mantle heater, and nitrogen gas was introduced through a glass nitrogen introduction tube to raise the temperature while keeping the inside of the reactor surrounded by an inert cloud.

Then, 13.2 g of p-)luenesulfonic acid was added and reacted at a temperature of 150°C. When the amount of distilled water reached 250, the reaction was stopped, and the reaction system was cooled to room temperature to produce crystalline polyester 1 made of polyhexamethylene sebacate having a hydroxyl group at the end of the molecule.

This crystalline polyester 1 has a melting point Tm of 64° C. and a weight average molecular weight Mw of 14.000.

(2) Crystalline polyester 2 Same as crystalline polyester 1, melting point Tm is 72°C
A crystalline polyester 2 made of polyethylene sebacate having a weight average molecular weight Mw of 12.800 was produced.

(3) Crystalline polyester 3 Same as crystalline polyester 1, melting point Tm is 92°C
A crystalline polyester 3 made of polyethylene succinate having a weight average molecular weight Mw of 14.800 was produced.

<Production of amorphous vinyl polymer> (1) Amorphous vinyl polymer 1 Put 100 parts by weight of toluene into a GLF separable flask, and add 75 parts by weight of styrene as a monomer for high molecular weight components, After adding and suspending and dispersing 25 parts by weight of n-butyl acrylate and 0.2 parts by weight of benzoyl peroxide, and replacing the gas phase in the flask with nitrogen gas,
The temperature was raised to 80° C. and maintained at that temperature for 15 hours to carry out the first stage polymerization. In addition, the weight average molecular weight Mw of the homopolymer of the monomer for the high molecular weight component is 461.000.
, the glass transition point Tg is 61°C.

Thereafter, the inside of the flask was cooled to a temperature of 40°C, and 85 parts by weight of styrene, 10 parts by weight of n-butyl methacrylate, 5 parts by weight of acrylic acid, and peroxide were added as monomers for low molecular weight components. After adding 4 parts by weight of benzoyl and continuing stirring at a temperature of 40°C for 2 hours, the temperature was increased to 80°C.
The temperature was raised again to 100 mL and maintained at that temperature for 8 hours to carry out the second stage polymerization. In addition, the weight average molecular fiMw of the homopolymer of the monomer for the low molecular weight component is 8.200, and the glass transition point Tg is 64°C.

Next, add 0 zinc oxide, which is a polyvalent metal compound, to the flask.
, 5 g was added thereto, and the reaction was carried out for 2 hours while maintaining the temperature at reflux and stirring.

After that, the reaction system is cooled to separate the solid matter, and after repeated dehydration and washing, it is dried to produce amorphous vinyl, which is produced by reacting zinc oxide with the carboxyl groups of the vinyl polymer to form ionic crosslinks. Polymer 1 was produced. Note that this amorphous vinyl polymer 1 has a carboxyl group as a functional group for bonding with the crystalline polyester.

This amorphous vinyl polymer 1 has two peaks in its molecular weight distribution by GPC, the peak molecular weight on the high molecular weight side is 363.000, and the peak molecular weight on the low molecular weight side is 7.000.
It is 590. In addition, the weight average molecular weight Mw is 165.0
00, the value of the ratio Mw/Mn is 25.9, the glass transition point Tg
is 62°C, and the softening point Tsp is 130°C.

(2) Amorphous vinyl polymer 2 Volume 11j! Put 100 parts by weight of toluene into a separable flask, and in it, 85 parts by weight of styrene, 10 parts by weight of n-butyl acrylate, 1 part by weight of acryloyloxyethyl monosuccinate, and 1 part by weight of benzoyl peroxide. After adding and suspending and dispersing the flask and replacing the gas phase in the flask with nitrogen gas, the temperature was raised to 80°C and maintained at that temperature for 5 hours to carry out polymerization.

Thereafter, 4 parts by weight of benzoyl peroxide was further added and polymerization was continued at a temperature of 80° C. for 10 hours.

Next, add 0 zinc oxide, which is a polyvalent metal compound, to the flask.
．． 5 g was added, and the reaction was carried out for 2 hours while maintaining the temperature at reflux and stirring.

Thereafter, toluene was distilled off using an aspirator and a vacuum pump to produce amorphous vinyl polymer 2 in which zinc oxide reacted with the carboxyl groups of the vinyl polymer to form ionic crosslinks. Note that this amorphous vinyl polymer 2 has a carboxyl group as a functional group for bonding with the crystalline polyester.

This amorphous vinyl polymer 2 has one peak in the molecular weight distribution by GPC, and the weight average molecular weight Mw is 8.
3.000, the value of the ratio Mw/Mn is 7.5, the glass transition point Tg is 67°C, and the softening point Tsp is 127°C.

(3) Amorphous vinyl polymer 3 In the production of amorphous vinyl polymer 1, 75 parts by weight of styrene, 20 parts by weight of n-butyl acrylate, and 5 parts by weight of glycidyl methafrylate were used as monomers for high molecular weight components. and 0.2 parts by weight of benzoyl peroxide 30
Styrene 75 as a monomer for low molecular weight components.
parts by weight, 10 parts by weight of n-butyl acrylate, 1 part by weight of methyl methacrylate, 2.5 parts by weight of glycidyl methacrylate, 2.5 parts by weight of acryloyloxyethyl monosuccinate, and 4 parts by weight of benzoyl peroxide. An amorphous vinyl polymer in which zinc oxide reacts with the carboxyl groups of the vinyl polymer to form ionic crosslinks was produced by the same treatment except that 100 g of the mixture was used. Note that this amorphous vinyl polymer 3 has an epoxy group as a functional group for bonding with the crystalline polyester.

This amorphous vinyl polymer 3 has two peaks in its molecular weight distribution by GPC, the peak molecular weight on the high molecular weight side is 473.000, and the peak molecular weight on the low molecular weight side is 7.000.
It is 940. In addition, the weight average molecular weight MW is 186.0
00, the value of the ratio My/Mn is 33.1, the glass transition point Tg is 62°C, and the softening point Tsp is 136°C.

By the way, the weight average molecular weight Mw of the homopolymer of the monomer for the high molecular weight component is 925.000, and the glass transition point T
g is 62°C, the weight average molecular weight Mw of the homopolymer of the monomer for the low molecular weight component is 9.610, and the glass transition point Tg is 63°C.

(4) Amorphous vinyl polymer 4 (for comparison) Vinyl polymer 4 for comparison was produced in the same manner as in the production of amorphous vinyl polymer 1, except that zinc oxide was not added. This comparative amorphous vinyl polymer 4 has a carboxyl group as a functional group for bonding to the crystalline polyester.

This comparative amorphous vinyl polymer 4 has two peaks in its molecular weight distribution by GPC, with the peak molecular weight on the high molecular weight side being 355.000 and the peak molecular weight on the low molecular weight side being 6.840. In addition, the weight average molecular weight Mw is 1
42.000, the value of the ratio Mw/Mn is 24.5, the glass transition point Tg is 60°C, and the softening point Tsp is 128.5°C.

Production of resin for toner> (1) Resin A for toner 15 parts M of crystalline polyester I and vinyl polymer 1
085 parts by weight of p-toluenesulfonic acid, 0.05 parts by weight of p-toluenesulfonic acid, and 100 parts by weight of xylene were placed in a separable flask with a capacity of 3 p, and refluxed at a temperature of 150°C for 1 hour. The mixture was distilled off using a vacuum pump to produce toner resin A consisting of a graft copolymer of crystalline polyester and ionically crosslinked amorphous vinyl polymer.

(2) Toner Resin B-D In the production of the above toner resin, the crystalline polyester and non-ionically crosslinked polyester were used in the same manner except that the combinations of the crystalline polyester and the amorphous vinyl polymer were changed to those shown in Table 1 below. Toner resins B to D each made of a graft copolymer with a regular vinyl polymer were produced.

(3) Resin E for toner (for comparison) In the production of resin A for toner, a graft copolymer was produced in the same manner except that comparative amorphous vinyl polymer 4 was used instead of amorphous vinyl polymer 1. A toner resin E consisting of the following was produced.

<Manufacture of toner> (1) Toners 1 to 4 10 each of the above copolymers A to D as toner resins
0 parts by weight of carbon black, 10 parts by weight of carbon black "Mogull LJ" (manufactured by Cabot), and 3 parts by weight of fixing property improver "Wax EJ (manufactured by Hoechst), melted and kneaded with heated rolls, and after cooling. , coarsely pulverized, further finely pulverized using a supersonic jet mill, and classified using an air classifier to obtain a powder.

To 100 parts by weight of this powder, 0.8 parts by weight of hydrophobic silica fine powder "Aerosil R-972J (manufactured by Nippon Aerosil Co., Ltd.) was mixed in a V-type mixer to obtain an average particle size of 11.07z.
Toners 1 to 4 according to the present invention of m were manufactured.

(2) Comparative Toner 1 Toner 1 was produced in the same manner except that toner resin A was changed to toner resin 2, with an average particle size of 11.0μ.
A counterfeit comparison toner 1 was produced.

(3) Comparative Toner 2 Toner I was produced in the same manner except that toner resin A was changed to a simple mixture of 1015 parts by weight of crystalline polyester and 85 parts by weight of vinyl polymer 1, and the average particle diameter Comparative Toner 2 with a 11.0μ layer was produced.

(4) Comparative Toner 3 Comparative Toner 3 having an average particle size of 11.0 μm was produced in the same manner as Toner 1 except that the toner resin A was changed to only Amorphous Vinyl Polymer 1.

(1) Organic latent image carrier A negatively charged organic latent image carrier formed using 2,7-dibromoanthurone as a carrier generating substance and a styryl triphenylamino compound as a carrier transporting substance. An organic latent image carrier was manufactured by laminating a two-layered photosensitive layer on a rotating drum-shaped aluminum conductive support.

(2) Selenium latent image carrier A selenium latent image carrier was manufactured by laminating a photosensitive layer made of selenium on a rotating drum-shaped aluminum conductive support.

<Examples 1 to 4> Electrophotographic copying machine rU-Bix 15 equipped with the above organic latent image carrier, a developing device for a two-component developer, and a heating roller fixing device
50J (Konica @ 1) A modified machine was used to mix each of toners 1 to 4 with an electrophotographic copying machine "U-Bix 155" under normal temperature environmental conditions (temperature 20°C, relative humidity 60%).
The electrostatic latent image was developed using each two-component developer with a toner concentration of 4% by weight prepared by mixing with a carrier for 0J (manufactured by Konica), and the toner image obtained by the development was 64g. /ω2 paper to form an unfixed toner image.

(1) Low-temperature fixability evaluation test A heating roller with a diameter of 30non whose surface layer is made of Teflon (polytetrafluoroethylene) and whose surface layer is silicone rubber rKE-1300RTVJ (manufactured by Shin-Etsu Chemical Co., Ltd.)
The above-mentioned unfixed toner image is fixed by a heating roller fixing device having a pressure roller of , the set temperature of the heating roller was changed stepwise by 5 degrees Celsius, and Kimwibe rubbing was applied to the obtained fixed toner image.
The lowest set temperature (minimum fixing temperature) for a fixed toner image exhibiting sufficient abrasion resistance was measured. Note that the heating roller fixing device is not equipped with a mechanism for applying a release agent such as silicone oil.

(2) Offset resistance evaluation test Immediately after forming a fixed toner image in the same manner as in the low-temperature fixing evaluation test above, a blank recording material was sent to the heating roller fixing device under the same conditions to avoid toner stains on it. An operation for visually observing whether toner staining occurred was performed at each set temperature of the heating roller, and the lowest set temperature at which toner staining occurred (offset generation temperature) was measured.

(3) Preservability evaluation test 2g of each of the above toners 1 to 4 was taken into a sample tube, tapped 500 times with a tap denser, and then heated to 55°C.
, left in an atmosphere with relative humidity of 26% for 2 hours,
Thereafter, the mixture was separated using a 48-mesh sieve, and the proportion of aggregates remaining on the sieve was measured.

(4) High temperature and high humidity environmental conditions (temperature 33℃, relative humidity 80℃)
%) toner charge amount After evaluating the low temperature fixability above, each developer was left under high temperature and high humidity environmental conditions (temperature 33°C, relative humidity 80%) - day and night.
Immediately after that, the toner charge amount was measured by a known blow-off method.

(5) High temperature and high humidity environmental conditions (temperature 33℃, relative humidity 80℃)
%) image quality Electrophotographic copying machine rU-8ix 15 equipped with the above-mentioned organic latent image carrier, a developing device for two-component developer, and a heated roller fixing device.
50J (Konica side) A photocopying test was conducted using a modified machine to form a copy image using each of the above developers under high temperature environmental conditions (temperature 33°C, relative humidity 80%). Image quality was visually evaluated.

Comparative Example 1> Toner 1 and electrophotographic copying machine rU-8ix 1600
A two-component developer with a toner concentration of 4% by weight is prepared by mixing with a carrier for J (Konica side), and this developer is used to develop the selenium latent image carrier and the two-component developer. Electrophotographic copying machine rU- equipped with a developing device and a heated roller fixing device
Evaluation was carried out in the same manner as in the above example except that a modified Bix 1600J (manufactured by Konica ■) was used.

Comparative Examples 2 to 4> Comparative toners 1 to 3 and electrophotographic copying machine "U-BiX"
Evaluations were made in the same manner as in the above examples, except that each two-component developer having a toner concentration of 4% by weight, which was prepared by mixing with a carrier for "1550" (manufactured by Konica ■), was used.

The above results are shown in Table 1.

As can be understood from the results in Table 1, according to the image forming method of the present invention, all of (1) low temperature fixability, (2) offset resistance, (3) storage stability, and (4) developability are achieved. Excellent performance is demonstrated in this respect.

On the other hand, in Comparative Example 1, since the latent image carrier is a selenium latent image carrier, the image has shading and the image quality is poor.

In Comparative Example 2, since the amorphous vinyl polymer constituting the toner resin E is not an ionically crosslinked amorphous vinyl polymer, the storage stability is extremely poor, and therefore the durability is also extremely poor.

In Comparative Example 3, the toner resin was a mere mixture of crystalline polyvinysthyl and an ionically crosslinked amorphous vinyl polymer, so it was inferior in terms of low-temperature fixing properties, anti-offset properties, and storage stability.

In Comparative Example 4, the toner resin was composed only of an ionically crosslinked amorphous vinyl polymer, so the low temperature fixability was poor.

Claims (1)

[Claims] 1) Using a toner containing a block copolymer or a graft copolymer formed by chemically bonding a crystalline polyester and an ionically crosslinked amorphous vinyl polymer, An image forming method comprising developing an electrostatic latent image formed on a latent image carrier made of a conductive semiconductor. 2) Claims characterized in that the ionically crosslinked amorphous vinyl polymer is formed by reacting a polyvalent metal compound with the carboxyl group of a vinyl polymer having a carboxyl group to form an ionically crosslinked bond. The image forming method according to item 1. 3) Claim 1 or 2, characterized in that the ratio Mw/Mn of the weight average molecular weight Mw to the number average molecular weight Mn of the ionically crosslinked amorphous vinyl polymer is 3.5 or more. The image forming method described in section. 4) The functional group chemically bonded to the crystalline polyester in the ionically crosslinked amorphous vinyl polymer is a carboxyl group, a hydroxyl group, an amino group, or an epoxy group. The image forming method according to any one of items 3 to 3. 5) The image according to any one of claims 1 to 4, wherein the ionically crosslinked amorphous vinyl polymer has at least two maximum values in its molecular weight distribution. Formation method.